Ski-Doo Formula S 1998, Shop Manual

Page: 79 / 338

Section 04 ENGINE
Subsection 02 (277 ENGINE TYPE)
04-02-4
TROUBLESHOOTING
Before completely disassemble engine, check air-
tightness. Refer to LEAK TEST AND ENGINE DI-
MENSION MEASUREMENT 04-04.
NOTE: The following procedures can be done
without removing the engine from chassis.
TOP END REMOVAL (without
removing engine from chassis)
Remove the following then lift cylinder head no. 3
and cylinder no. 4 :
– belt guard
– carburetor
– exhaust system
– spark plug
– oil injection inlet
– fan cowl and hood cable
– cylinder head nuts no. 1 and washers no. 2
CLEANING
Discard all gaskets.
Clean all metal components in a non-ferrous met-
al cleaner.
Scrape off carbon formation from cylinder ex-
haust port, cylinder head and piston dome using a
wooden spatula.
NOTE: The letters “AUS” (over an arrow on the
piston dome) must be visible after cleaning.
Clean the piston ring grooves with a groove clean-
er tool, or with a piece of broken ring.
DISASSEMBLY
5, Piston
On this engine, piston pin needle bearing no. 6 is
mounted without a cage.
Use piston pin puller (P/N 529 0290 00) along with
expansion sleeve and locating sleeve.
Place a clean cloth or rubber pad (P/N 529 0234
00) over crankcase to prevent circlips
no. 8 from
falling into crankcase. Then with a pointed tool in-
serted in piston notch, remove circlips from pis-
ton
no. 5 .
Insert piston pin puller (P/N 529 0290 00) then in-
stall expansion sleeve over puller rod.
1. Expansion sleeve
Pull out piston pin no. 7 by unscrewing puller until
first thread of puller rod aligns with 277 mark.
1. 277 mark on puller
A21C06B
1
529 0290 00
A21C05A
1